People's requirements realism and purity are more and higher in the case of collecting, displaying and printing of the image/video. Meantime, capturing during the process of display, non-matching and non-linearity characters between sensitization elements of a capturing apparatus for capturing an image of display and luminescence/color elements of a display/print apparatus cause that these capturing data must be reprocessed to recover nature color and avoid the color component not suitable for human eyes as possible under the existing parts of a physical apparatus. Since requirements for interested color of human eyes under different environments demand that factual collecting and capturing apparatus of image/video have functions of enhancing, modifying and adjusting. For example, there's image saturation, color adjustment and specific color enhancing and modifying function in a TV and video camera.
The existing display apparatus has the function of whole modification of color and hue for image/video, especially to saturation, color/hue and so on. One of the simplest and most universal apparatus and method is as follows. First, color space conversion module converts image/video from RGB or CMYK etc. color space to YUV or YCbCr etc. color space. Second, coordinates conversion module separates a color component into dependent component such as saturation, color/hue. Then in the case of modifying the saturation component, saturation modification module modifies a saturation component to multiply by a component α, when α>1, the whole image/video saturation is enhanced; For modifying image/video color saturation, hue modification module modifies the phase of a UV plane by adding a chroma component θ to change the hue of the whole image/video.
However, all these adjusting functions can not be used in a specific region of the color space but in the whole color space. Therefore, in such above-presented method, there are a lot of defects as following: 1. Overly adjusting the saturation of the image/video possibly so as to color the gray scale strip and achromatous object, even color some objects out of bound to be another unacceptable color for human eyes, for example, human face is changed in red. 2. Simply adjusting the saturation of color may cause some data extending out of the largest range to shrink the factual color space, therefore, lowering the image/video quality to some extent. 3. In the case where the hue of some colors is to be modified, the hue of other colors is wrongly changed at the same time possibly. Such a case needs us to avoiding.